Automatic train control



3 1930; D. H SCHWEYER' 1,758,765

AUTOMATIC TRAIN CONTROL Filed Feb. 27, 1928 Patented May 13, 1930 PATENTOFFICE DANIEL HERBERT SOHWEYER, OF EASTON, PENNSYLVANIA AUTOMATIC TRAINCONTROL Application filed February 27, 1928. Serial No. 257,345.

The present invention relates to train control apparatus, and aims toprovide a simple,

practical and reliable apparatus for obtaining three condition control,such as for danger, caution and clear conditions when pass= ing controllocations of the track.

Another object of the invention is the provision of such an apparatuswhich will obtain three-condition control by the use of two pairs ofinductors on the train and track, and which inductors may be of simpleconstruction,

without requiring trackside energy.

With the foregoing and other objects in view, which will be apparent asthe description proceeds, the invention resides in the construction andarrangement of parts, as hereinafter described and claimed, it beingunderstood that changes can be made within the scope of what is claimed,without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein thefigure is a diagram of the apparatus.

The train equipment, which may be carried by the locomotive, car orother vehicle, includes electro-pneumatic valves 1 and 2, or othersuitable translating or controlling devices, for controlling the brakesof the train, the electro-pneumatic valve 1 being energized for clearconditions, the electro-pneumatic valve 2 being energized for cautionconditions with the valve 1 deenergized, and both valves beingdeenergized for danger conditions.

Any suitable air brake equipment may be employed, for example, asdisclosed in my Patents Nos. 1,279,454 and 1,389,602, granted September17, 1918 and September 6, 1921, or

in my copending application Serial No.

698,533, filed March 11, 1924.

The valve 1 is disposed in a normally closed electrical circuitincluding the battery 3 or other source of electrical energy, conductor4, valve 1, conductor 5, switch 6, contact 7, conductor 8, contact 9,switch 10 and conductor 11. The valve 2 is similarly included in anormally closed circuit under both clear and caution conditions, andsuch circuit includes the battery 3, conductor 4, valve 2, conductor 12,contact 13, switch 14, conductor 15, contact 16, switch 17 and conductor11.

The switches 6 and 14 are controlled by electro-magnets 18 and 19,respectively, connected between the conductor 4 and the conductors 5 and12, respectively, whereby said magnets 18 and 19 are connected inparallel or multiple with the valves 1 and 2, respectively. Similarly,clear and caution electric lamps 20 and 21 are connected between theconductor 4 and the conductors 5 and 12, respectively, in parallel ormultiple with the respective magnets 18, 19 and valves 1, 2.Consequently, the valve 1, magnet 18 and lamp 20 are simultaneouslyenergized, and the valve 2, magnet 19 and lamp 21 are simultaneouslyenergized. .The magnets 18 and 19 with their switches 6 and 13,respectively, provide stick relays in order that when said magnets aredeenergized, the switches thereof remain open, to break the circuits andsaid circuits can only be restored by returning the switches to raisedpositions. Said relays may be under lock and key, in order that they mayonly be restored by the authorized person, such as the conductor of thetrain.

A danger electric lamp 22 is connected between the conductor 4 and aconductor leading to a contact 24 onto which the switch 13 drops whenthe magnet 19 is deenergized.

The switches 10 and 17 are controlled by the electromagnets 25 and 26,respectively, a

is an exciting coil or electromagnet, while the coil 28 is an impulsecoil,being energized with weaker current from the battery 29. A U-shaped core 33 is mounted on the trackside at each control location, andhas a choke coil 34 thereon disposed in the circuit 35 'including aswitch 36 controlled by a signal electromagnet 37 which magnet isenergized for clear track conditions and is deenergized for caution anddanger track conditions. When the switch 36 is open, the choke coil 34isiniii) effective, so that the core 33 is efiective to influence thevehicle-carried inductor. Gonsequently, when the core 30 passes over thecore 33 in inductive relation therewith, the core 33 completes themagnetic circuit of the core 30, with short air gaps between the ends ofthe cores, and the reluctance of the magnetic circuit of the vehicleinductor is therefore momentarily decreased, inasmuch as the reluctanceof the core 33 is less than that of the normal long air gap between theends of the core 30. Consequently, there is a surge of magnetic fluxfrom the core 30 through the core 33, in the magnetic circuit thereof,which induces a single wave of alternating current in the coil 28, andone-half of the wave opposes the battery 29, thereby deenergizing themagnet 25 and releasing the switch 10.

This action will not take place if the switch 36 is closed, on accountof the fact that the choke coil 34 impedes the flow of magnetic fluxthrough the core 33.

The electromagnet 26 is controlled in substantially the same manner asthe electromagnet 25, bein disposed in a circuit 38 with the impulsecoir 33 and battery 40, and said impulse coil 39 is disposed on a core41 with an exciting coil or electromagnet 42 energized by the strongerbattery 43. A core 44 is mounted on the trackside at each controllocation, being a companion for the core 33, and has a choke coil 45thereon disposed in a circuit 46 with the switch 47 controlled by thesignal electromagnet 48. In the arrangement shown the magnet 48 isenergized for both clear and caution conditions, and is de energized fordanger conditions. The magnets 37 and 48 may be located in the waysidesignal circuits or may be controlled in any suitable manner, or theswitches 36 and 47 may be controlled electrically, manually,mechanically or otherwise, the control of said switches forming no partof the present invention.

lVhen the train is proceeding under clear conditions, the valves 1 and2, and magnets 18, 19, 25 and 26 are energized, to complete the circuitsof the vehicle equipment, as above described, and the lamps 20 and 21are lighted, to indicate that both the clear and caution means are inorder, but clear condi tions prevail as long as the lamp 20 is lightedand the valve 1 is energized. WVith the choke coil circuits on the trackclosed, the vehicle inductors pass the trackside inductors without anyefiect being obtained.

Under caution conditions, the switch 36 is open, and the switch 47closed, so that when the vehicle inductors pass over the tracksideinductors, the electromagnet 25 is momentarily deenergized, therebydropping the switch 10, while the switch 17 remains closed. The magnet18 is therefore deenergized to release the switch 6, which remains downeven after the switch 10 is restored by the reenergization of the magnet25, and the circuits of the valve 1, magnet 18 and lamp 20 are thereforeinterrupted. The caution lamp 21 remains lighted, to indicate cautionconditions, and the valve 1 being deenergized, with the valve 2energized, will permit the train to proceed below a predeterminedcaution speed limit.

If the train passes the trackside inductors, with both switches 36 and47 open, both magnets 25 and 26 are deenergized, and the opening of theswitches 10 and 17 will deenergize the stick relay magnets 18 and 19,thereby resulting in the switches 6 and 14 being released and remainingin their lower positions. The lamps 20 and 21 are thereforeextinguished, and the valves 1 and 2 are deenergized, requiring thestopping of the train. The lamp 22 is lighted, following the restorationof the switch 17 after the vehicle inductors have passed beyond thetrackside inductors, its circuit including the battery 3, conductor 4,lamp 22, conductor 23, contact 24, switch 14, conductor 15, contact 16,switch 17 and conductor 11. This will indicate danger conditions to theengineer.

Clear and caution conditions can only be restored, after beinginterrupted, by the restoration of the switches 6 and 14, respectively,which may be under lock and key to require resetting by the authorizedperson, such as the conductor of the train.

Having thus described the invention, what is claimed as new is 1. Traincontrol apparatus comprising a plurality of electrical stick circuitseach including a stick relay, control devices controlled by said relays,a plurality of vehiclecarried inductors each including a core withexciting and impulse coils thereon both energized by direct current,normally energized relays connected to the impulse coils and havingnormally closed switches in said stick circuits, and trackside inductorsfor influencing the vehicle-carried inductors to deenergize the lastnamed relays.

2. Train control apparatus comprising a plurality of electrical stickcircuits each including a stick. relay, control devices controlled bysaid relays, vehicle-carried inductors, normally energized relayscont-rolled by said inductors and having normally closed switches insaid stick circuits, magnetic trackside elements for influencing thevehicle-carried inductors to deenergize said normally energized relays,choke coils on said elements, and means controlling the circuits of saidchoke coils.

3. Train control apparatus comprising a plurality of electrical stickcircuits each including a stick relay, control devices controlled bysaid relays, a plurality of vehiclecarried inductors each including acore with exciting and impulse coils thereon both energized by directcurrent, normally energized relays connected to the impulse coils andhaving normally closed switches in said stick circuits, magnetictrackside elements for influencing the vehicle-carried inductors to deenergize the lastnamed relays, choke coils on said trackside elements,and means controlling the circuits of said choke coils.

In testimony whereof I hereunto aflix my signature.

DANIEL HERBERT SCHWEYER.

